Spark plug



June 14, 1949. H. R. WEBBER sPARK PLUG Filed Jan. 29, 1946 larva/70R. Q 2411 KM. M

ATTORNEY,

Patented June 14, 1949 UNITED STATES PATENT OFFICE SPARK PLUG Harry R. Webber, Norwood, Pa.

Application January 29, -1946,-Serial No. 643,994

I 1 Claim.

The object of this invention is to devise a novel spark plug having spark intensifying means within the insulator and having means to vent a chamber surrounding the insulator tothe atmosphere.

A further object of the invention is to devise a novel insulator.

With the foregoing and other. objects in view as will hereinafter clearly appear, my invention comprehends a novel spark plug having novel intensifying means for the spark.

It further comprehends a novel spark plug wherein the insulator is constructed in a novel manner to provide for a spark intensifier within the insulator and vented to the atmosphere.

For the purpose of illustrating the invention, I have shown in the accompanying drawings a preferred embodiment which, in practice, will give satisfactory and reliable results, It is, however, to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and the invention is not limited to the exact arrangement and organization of these instrumentalities as herein set forth.

Figure 1 is a sectional elevation of a spark plug embodying my invention.

Figure 2 is a side elevation of the'insulator, showing also the main electrode.

Figure 3 is a top plan view of the construction shown in Figure 2.

Similar numerals of reference indicate corresponding parts.

Referring to the drawings:

The shell I is threaded as at 2 to adapt it to be screwed into position on the engine with which it is to be used.

The shell at its inner end has ground electrodes 3 and 4 which are deflected towards the lower section 5 of a main electrode to provide the proper spark gap. The section 5 of the main electrode is spaced at its outer end from the outer section 6 of the main electrode to provide a spark gap 1 which is preferably the same spacing as that between the ground electrodes 3 and 4 and the inner sec tion 5 of the main electrode.

The main electrode is secured in an insulator 8 having an aperture 9 extending laterally through it at the spark gap 1. The inner electrode section 5 is of greater diameter than the section 6 except at its outer portion where it is of reduced diameter to form a shoulder H] which abuts against a shoulder I l in the insulator.

The shell I has a differential bore, being of reduced diameter at l2, having a seat I3, a chamber l4 and an enlarged diameter l5 which forms a seat I6 at its inner end, and which has the outer portion of its wall internally threaded to receive a nut l1.

The insulator 8 has at its inner end a portion I8 to fit the diameter I2 of the shell and such portion merges into an outwardly diverging portion l9,

which in turn merges into a substantially straight portion 20. The portion 20 merges into a portion 2| of reduced diameter at its inner end and increasing in diameter towards its outer end where it merges into an enlarged portion 22. The outer end portion of the insulator is of reduced diameter.

with the seat l3 so that products of combustion cannot pass from the engine cylinder to the chamber M, and the outer end of the chamber It is sealed at the seat it.

The spark gap 7 materially intensifies the spark produced between the inner electrode section of the main electrode and the ground electrodes, and since'this spark gap 7 is within the insulator it is not subject to climatic conditions and. deleterious foreign material which might aifect the spark if the intensifier was on the spark plug or in the line leading to the spark plug.

Any heat in the chamber Hi can vent to the atmosphere through the slots 26 and 21 and the spark plug will be maintained at the proper temperature. 4

Having thus. described my invention, what I claim as new and desire to secure by Letters Patent is: a

In a spark plug, a shell having a diiierential bore with an annular internal portion at its forward end, a conical seat in rear of said annular portion and a rear, flat seat of greater diameter than said conical seat, an insulator in said shell having a cylindrical portion closing the front end of the shell, a conical seat in rear of said cylindricalportion, an enlarged rear shoulder to engage the rear seat, a portion of reduced diameter between said seats forming with the shell an annular chamber, and a lateral passage opening at its ends into said chamber, a nut encircling the 9,478,817 3 n 4 insulator, in threaded engagement with the shell REFERENCES CITED and bearing against said shoulder, said insulator having passages in its periphery extending from 3 g z z fi are of record the said lateral passage through its rear shoulder and beyond said nut, a ground electrode at the front 5 UNITED STATES PATENTS end of the shell, and a sectional main electrode ex- Number Name tending longitudinally through the shell with 1,206,736 stemberger g juxtaposed ends spaced at said lateral passage to 1,311,039 Barman July 1919 form a'spark gap of substantially the same spac- 1,327,382 Gamer Jan 1920 ing as that of the main and ground electrodes. m 1,437,659 Johnson Man 1924 1,721,158 Leonard July 16, 1929 HARRY WEBBER- 2,194,251 Walter et a1 Mar. 19. 1940 

